If you're looking for a PDF version of the book, I have some good news and some not-so-good news.
The primary strength of the series lies in its low barrier to entry. It is an excellent "bridge" resource—ideal for tourists, casual learners, or those intimidated by the "grammar-first" approach of university textbooks. The grammar points are broken down into bite-sized, digestible chunks, often using color-coding to highlight sentence structures.
– Focuses on immediate practical use.